Copilot seats for a small business, and the open-source option beside them

What a small business buys, line by line

Microsoft sells Copilot to a small company in two pieces. The Microsoft 365 Business plan comes first: Business Basic, Business Standard or Business Premium, with mail, files and the Office apps. The Copilot seat is added on top, per person. Microsoft's business pricing page sums the arrangement up as everyday AI inside the plan and the advanced work you hand off billed as you use it (Microsoft, checked October 2026).

Microsoft 365 Copilot Business is the version aimed at this size of company: an annual commitment, an eligible Business plan underneath today, and a ceiling of 300 people per tenant. A company past that number buys the enterprise options.

Microsoft lists Microsoft 365 Copilot Business (add-on) at $18 a person a month paid yearly, reduced from $21, or $25.20 billed monthly (Microsoft, checked October 2026). The $18 is a first-year promotional rate for existing Microsoft 365 customers on an eligible Business plan, and it runs to the end of 2026. Copilot Chat, the browser and Outlook assistant, comes at no extra cost with eligible Microsoft 365 plans, so a team already has a Copilot of sorts before it buys anything (what each free tier includes).

A twelve-person firm on Business Standard therefore carries a base plan it already pays, a seat line it can forecast at $216 a month at the promotional rate, and a third line that only appears once somebody hands real work to the advanced experiences. That third line is where small budgets lose their footing.

Why a seat count is the wrong planning unit

Seats are a headcount forecast, and adoption is never even across a team of five or of fifty. In twelve people, two will live in the app, four will use it for meeting recaps, and six will open it the week the invoice lands. All twelve cost the same.

The work that would pay for itself has a different shape. A month-end close over four hundred receipts, a backlog of support tickets, a hundred product descriptions, a rewrite program: those jobs are long and lumpy, and they do not divide into a per-person subscription. Some of them never pass through Word or Outlook at all.

Microsoft has moved part of the bill onto a meter as well. Its business page names the metered experiences as Copilot Cowork, Code, Autopilot and the Work IQ APIs, with spending policy managed in Cost Management in the Microsoft 365 admin center. A Copilot Business subscription bought through a Cloud Solution Provider after 1 December 2026 carries a preset allowance for each person each month that an admin can change (Partner Center).

Twelve times that per-person preset is 48,000 credits a month before anyone chooses a number. A forecast built on people cannot see that line. The credit arithmetic, at Microsoft's published rates, sits in the Kortix blog.

Buy the seats when the week lives in Outlook, Word and Teams

Plenty of small companies should buy the seats and stop there, and for most of them that is the right answer. If the week runs through Outlook, Word, Teams, Excel and SharePoint, Copilot is the cheaper buy and the better fit. It answers from the mail, files, chats and meetings the company already holds. The recap in Teams, the draft in Word, the summary of a long thread in Outlook: each is seconds of work inside the app where the person already sits.

The 300-person ceiling rarely binds, and purchasing and administration were designed for exactly this buyer. One admin center holds the seats.

A job that takes an hour and pulls from four systems needs somewhere to run, and the seat is not that place. A team that expects the seat to cover it will end the year doing the work by hand and paying for the subscription anyway.

Run the agent layer where the work is long, variable or file heavy

In Kortix, two controls carry their weight at this size. Per-resource permissions for people and agents. Roles, groups, and an audit trail. Approval gates you set. Off until you set them. A send, a merge or a payment stops where the owner says it stops, and the change lands in the repo as a diff somebody read first.

The meter fits variable work. Kortix pricing describes it in one line: "It bills per second while it runs and costs nothing while it is stopped." (checked October 2026). A seat bills for a person whether the app gets opened or not. A cloud computer bills for the job.

Open source. Read it, fork it, audit it. Run it on Kortix Cloud, in your VPC, or on your own on-prem network. Self-host is free.

A twenty-person company can hand over a long job, read the change request that comes back, and decide. The wider field, from document answering to agent runtimes, sits on the open-source Copilot alternatives list.

A month-long pilot that settles it for a small team

Assign the seats by week, not by headcount. Start with the people whose calendar and inbox are the work: an account manager in Outlook all day, a controller in Excel, a manager who runs six meetings a week. Six seats in a twelve-person firm is a pilot. Twelve is a subscription nobody has tested.

Give one long job to the other system in the same month, and pick something that already hurts and already crosses tools: invoices that arrive as PDFs, a ticket queue nobody has cleared, or forty product pages that need rewriting before a launch.

Read both bills at day thirty. Microsoft's business plans include adoption analytics, so the seat report answers how many people opened the app and how often. The agent side answers whether a finished thing came back. Keep the line that produced work and drop the seats nobody used. That decision costs one month and two bills, and it is the only test that separates the two purchases.

What the 1 December change looks like at twelve people

A renewal is the quiet case. A subscription that renews as it stands keeps its seat count, its per-person rate and its monthly total on the provider invoice, and Microsoft asks the customer for nothing. The bill changes when somebody buys a new subscription through a reseller after 1 December: that one arrives with the meter already switched on, so the invoice carries the seat line plus a usage line from the first month, and the usage line follows the work rather than the headcount. The Microsoft 365 Copilot add-on page works through the December mechanics line by line.